Description:
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1. The selected item overlaps on drop down button of non-editable combobox and the button doesn't shifted to left from right.

2. The drop down button shifts to left from right in editable combobox but it looks detach with the textfield.

3. Key bindings are not working for combobox.Only mouse bindings are working.

4.Drop down button is hiding while keep press on button of editable combobox.

JDK Info:
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java version "1.6.0_04"
Java(TM) SE Runtime Environment (build 1.6.0_04-b01)
Java HotSpot(TM) Client VM (build 1.6.0_03-ea-b02, mixed mode)

Steps to reproduce:
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1. Download the attached java file and execute with above specified jdk build.
2. Choose the nimbus look and feel from the menu.

Now you can see the above specified issues.